Nimodipine is a dihydropyridine derivative calcium channel blocker indicated for the improvement of neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage (SAH) from ruptured intracranial berry aneurysms regardless of their post-ictus neurological condition (i.e., Hunt and Hess Grades I-V). Nimodipine has the chemical name 1,4-dihydro-2,6-dimethyl-4-(m-nitrophenyl)-3,5-pyridinedicarboxylate and the structure shown below:

NIMOTOP® (Bayer Pharmaceuticals Corp.) is a liquid-filled capsule formulation of nimodipine for oral dosing. Each NIMOTOP® capsule contains 30 mg of nimodipine and is commonly administered in a two-capsule 60 mg dose.
The prescribing information for NIMOTOP® states that, if the capsule cannot be swallowed (e.g., at the time of surgery) or if the patient is unconscious, a hole should be made in both ends of the capsule with an 18 gauge needle, and the contents of the capsule extracted into a syringe. To help minimize administration errors, it is recommended that the syringe be labeled “Not for IV Use”. The contents should then be emptied into the patient's in situ naso-gastric tube and washed down the tube with 30 mL of normal saline (0.9%).
In addition to this method of delivery being cumbersome and time consuming, it is also dependent on the ability of the particular practitioner. It is possible that the practitioner extracts less than the full amount of the liquid dose from the capsule, leading to under dosing and insufficient treatment.
NYMALIZE® (Arbor Pharmaceuticals, LLC) was the first marketed oral nimodipine solution, eliminating the need for needle extraction of nimodipine from capsules for patients that cannot consume capsules. NYMALIZE® is supplied in bottles that should be stored between 20° C. to 25° C. (68° F. to 77° F.), protected from light, and un-refrigerated. The recommended dose is 20 mL (containing 60 mg of nimodipine) every 4 hours for 21 consecutive days. The inactive ingredients in NYMALIZE® are ethanol, glycerin, methylparaben, polyethylene glycol, sodium phosphate monobasic and water (about 20% by volume).
It has been found that NYMALIZE® slowly degrades under certain conditions (e.g., elevated temperature and humidity). One of the degradants includes nimodipine related compound A, (2-Methoxyethyl 1-methylethyl 2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylate) having the following structure:

Accordingly, there remains a need for liquid nimodipine formulations with improved stability and decreased degradation.